Industrial Control Systems Based On Three-tier Architecture And Xml Data Integration Software Research And Development Of The Middle Layer

Generally industry information system is depended on multi-subsystems of different functions, but the method of traditional data exchange among them has no standards, so there are many problems such as: many interfaces, poor accessibility and security and etc, this brings on many "information island". We must smash information bulwark, only good cooperation among sub-systems can make the enterprise more efficacious, so we need a data platform that has uniform data description, accessing standards and the feature of good opening to get data from every sub-system and give it to every department, the platform is a bridge between controlling layer and management layer, only in a good data service environment we can easily share and exchange information.Under this technology background, This paper aimed at the problem of lack of data exchange standards in heterogeneous supervisor subsystem, proposed the idea that built industry information integrated platform based on XML and three-tier (n-tier) software architecture to share data, Three hard points that were met in developing system included the realization of three-tier (n-tier) architecture, the data amalgamation in heterogeneous supervisor subsystems, and remote monitoring and controlling. In the discussion of DNA, I mainly discussed the fault of two-tier architecture and the virtue of three-tier (n-tier) architecture and proposed a simple three-tier data amalgamation software based on the technique of DDE, Socket and ADO, and the main techniques of data sharing based on web are XML, ASP and IIS, the database was SQL Server2000. In the discussion of the data exchange standard in different supervisor subsystems, I mainly discussed the fault of DDE and the virtue of OPC, then particularly introduced the technique of COM/DCOM, besides proposed to realize a strong data exchanging platform of three-tier structure based on OPC in the category of COM+. In the discussion of remote controlling, the paper gives two method of remote controlling, and selected the method of remote image monitoring and controlling to screen the difference between supervisor software. If given access rights, legal uses can access and control the remote industrial workstation so as to do something like remote diagnosing, maintenance, etc, then talked about the problems and the methods to solve them. In the chapter of sum-up, the paper mainly discussed the problems, experience in the programming, and probed into later work and directions, at last talked about the realization of industry information platform in the future.